1. Field of the Invention
The present invention relates to the field of data entry and retrieval and, more particularly, to a method and system for indicating the existence of annotations made for a variety of heterogeneous data objects.
2. Description of the Related Art
An annotation system is used to create, store, and retrieve descriptive information about objects. Virtually any identifiable type of object may be annotated, such as a matrix of data (e.g., a spreadsheet or database table), a text document, or an image. Further, subportions of objects (sub-objects) may be annotated, such as a cell, row, or column in a database table or a section, paragraph, or word in a text document. Some annotation systems store annotations separately, without modifying the annotated data objects themselves. For example, annotations are often contained in annotation records stored in a separate annotation store, typically a database. The annotation records typically contain information about the annotations contained therein, such as the creation date and author of the annotation, and an identification of the annotated data object, typically in the form of an index.
An indexing scheme is typically used to map each annotation to the annotated data object or sub-object, based on the index. Therefore, the index must provide enough specificity to allow the indexing scheme to locate the annotated data object (or sub-object). Further, the indexing scheme must work both ways: given an index, the indexing scheme must be able to locate the annotated data object and, given an object, the indexing scheme must be able to calculate the index for use in classification, comparison, and searching (e.g., to search for annotations for a given data object). Databases are typically used as the annotation store for performance reasons, so that annotation records can be efficiently stored and retrieved.
When a user views a portion of a data (e.g., results received in response to issuing a query), it is generally desirable to display annotations made for data objects in the view. The fact that the annotations and the data described by the annotations may be stored in totally separate data stores may present a problem, however, as there is currently no readily available technique for tying together data from totally separate data stores. For example, the data source and annotation store typically have no primary keys in common form that can be used for a standard join.
Accordingly, there is a need for a method for identifying and indicating annotations made for a variety of different type data objects.